avoid-drop-reference-to-iloc.bh-twice

   1 ext4: avoid drop reference to iloc.bh twice
   2
   3 From: Pan Bian <bianpan2016@163.com>
   4
   5 The reference to iloc.bh has been dropped in ext4_mark_iloc_dirty.
   6 However, the reference is dropped again if error occurs during
   7 ext4_handle_dirty_metadata, which may result in use-after-free bugs.
   8
   9 Fixes: fb265c9cb49e("ext4: add ext4_sb_bread() to disambiguate ENOMEM
  10 cases")
  11
  12 Signed-off-by: Pan Bian <bianpan2016@163.com>
  13 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  14 Reviewed-by: Jan Kara <jack@suse.cz>
  15 ---
  16  fs/ext4/resize.c | 1 +
  17  1 file changed, 1 insertion(+)
  18
  19 diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
  20 index e7ae26e..4d5c0fc 100644
  21 --- a/fs/ext4/resize.c
  22 +++ b/fs/ext4/resize.c
  23 @@ -874,6 +874,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
  24         err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
  25         if (unlikely(err)) {
  26                 ext4_std_error(sb, err);
  27 +               iloc.bh = NULL;
  28                 goto errout;
  29         }
  30         brelse(dind);
  31 --
  32 2.7.4
  33
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  35